Docset index contains relocated symbols that only result in a redirection about cargo-docset

[Robzz]

Thanks for this report and the other ones, I'll look into this and make a new release.

[Robzz]

I finally looked into this and it appears redirection pages now include <title>Redirection</title> in the head section, which is probably the easiest way to identify them. I implemented this in #45 which seems to work and I haven't noticed any missing entries as a consequence. Docset generation does seem a bit slower as a result of reading the beginning of every HTML page, but it's still fast enough that I didn't feel the need to measure it.

I'll make a point release in a few days if I don't notice anything wrong by then.